Thursday, December 06, 2012

James Shapiro Never Learns

One of the remarkable things about kooks is that they are incredibly resistant to learning from their mistakes. James Shapiro gives us a fine example in one of his latest articles on The Huffington Post where he tries to convince us that the old definition of "gene" has outlived its usefulness. According to Shapiro, "DNA and molecular genetics have brought us to a fundamentally new conceptual understanding of genomes, how they are organized and how they function."

Really? While we all can agree that there's no definition of "gene" that doesn't have exceptions, we can surely agree that some definitions work pretty well. I've argued that defining a gene as, "a DNA sequence that is transcribed to produce a functional product" works well in most cases [What Is a Gene?].

Let's see how James Shapiro handles this problem.1 He says,

The identification of DNA as the key molecule of heredity and Crick's Central Dogma of Molecule Biology [Crick 1970] initially seemed to confirm Beadle and Tatum's "one gene -- one enzyme" hypothesis.

The Central Dogma says that "... once (sequential) information has passed into protein it cannot get out again." In other words, you can't transfer sequence information from protein to nucleic acid [Basic Concepts: The Central Dogma of Molecular Biology]. This has nothing to do with the concept of a gene and it certainly doesn't confirm the old "one gene—one enzyme" hypothesis. At the time that Crick wrote his 1970 Nature paper—the one always referred to by Shapiro—he certainly knew about genes for ribosomal RNA and genes for tRNAs. These are clear examples of genes that don't encode proteins.

Shapiro has read my blog and he has read my review. Presumably he has by now (re)read Crick's 1970 paper. So how come he still doesn't get it?

Shapiro continues ...

However, molecular genetics quickly introduced difficulties with the theory of atomistic genes aligned like beads on a string.

A major challenge was Britten and Kohne's1968 discovery of massive amounts of repetitive DNA in certain genomes. Today, we know our DNA contains over 30 times as many base-pairs in repeats as it does in protein coding sequences. By the conventional view, if genes are the only important actors, then these surprisingly abundant "intergenic" repeats must constitute "junk DNA" and be "ultimate parasites" in the genome.

None of this was a challenge to our concept of "gene" because junk DNA and repetitive DNA isn't genes. Now, maybe if you believed that all genes encode proteins back in 1970 you might have been confused by all that, but most of us abandoned Beadle and Tatum almost fifty year ago. Apparently Shapiro is a slow learner.

As readers of this and other science blogs know well, the junk DNA idea has been challenged by the large-scale ENCODE project, designed to produce the "Encyclopedia Of DNA Elements" independently of theoretical prejudices. In its first few years, ENCODE has documented cell type-specific biochemical activity in over 80 percent of this repetitive DNA and known functions in 20 percent.

The basic issue is that molecular genetics has made it impossible to provide a consistent, or even useful, definition of the term "gene."

Oh dear! Most intelligent molecular biologists are well aware of the problems with the ENCODE claim. Shapiro isn't.

But even if ENCODE's most incredible claim were true it still wouldn't have any effect on our definition of "gene." If lots of our genome is transcribed into functional RNA molecules then it simply means that we have more genes than we originally thought. If lots of the genome consists of regulatory sequences and DNA binding sites then that's fine too. These aren't genes—they are sequence that regulate the expression of genes.

Since the 1970s it's been possible to think of a gene as a "DNA sequence that's transcribed" without inducing any brain seizures. Nothing has changed since then in spite of what James Shapiro would have you believe.

Laurence A. Moran

Larry Moran is a Professor in the Department of Biochemistry at the University of Toronto. You can contact him by looking up his email address on the University of Toronto website.

Sandwalk

The Sandwalk is the path behind the home of Charles Darwin where he used to walk every day, thinking about science. You can see the path in the woods in the upper left-hand corner of this image.

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Some readers of this blog may be under the impression that my personal opinions represent the official position of Canada, the Province of Ontario, the City of Toronto, the University of Toronto, the Faculty of Medicine, or the Department of Biochemistry. All of these institutions, plus every single one of my colleagues, students, friends, and relatives, want you to know that I do not speak for them. You should also know that they don't speak for me.

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Quotations

The old argument of design in nature, as given by Paley, which formerly seemed to me to be so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows.Charles Darwin (c1880)Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory.

Charles Darwin (1859)Science reveals where religion conceals. Where religion purports to explain, it actually resorts to tautology. To assert that "God did it" is no more than an admission of ignorance dressed deceitfully as an explanation...

Quotations

The world is not inhabited exclusively by fools, and when a subject arouses intense interest, as this one has, something other than semantics is usually at stake.
Stephen Jay Gould (1982)
I have championed contingency, and will continue to do so, because its large realm and legitimate claims have been so poorly attended by evolutionary scientists who cannot discern the beat of this different drummer while their brains and ears remain tuned to only the sounds of general theory.
Stephen Jay Gould (2002) p.1339
The essence of Darwinism lies in its claim that natural selection creates the fit. Variation is ubiquitous and random in direction. It supplies raw material only. Natural selection directs the course of evolutionary change.
Stephen Jay Gould (1977)
Rudyard Kipling asked how the leopard got its spots, the rhino its wrinkled skin. He called his answers "just-so stories." When evolutionists try to explain form and behavior, they also tell just-so stories—and the agent is natural selection. Virtuosity in invention replaces testability as the criterion for acceptance.
Stephen Jay Gould (1980)
Since 'change of gene frequencies in populations' is the 'official' definition of evolution, randomness has transgressed Darwin's border and asserted itself as an agent of evolutionary change.
Stephen Jay Gould (1983) p.335
The first commandment for all versions of NOMA might be summarized by stating: "Thou shalt not mix the magisteria by claiming that God directly ordains important events in the history of nature by special interference knowable only through revelation and not accessible to science." In common parlance, we refer to such special interference as "miracle"—operationally defined as a unique and temporary suspension of natural law to reorder the facts of nature by divine fiat.
Stephen Jay Gould (1999) p.84

Quotations

My own view is that conclusions about the evolution of human behavior should be based on research at least as rigorous as that used in studying nonhuman animals. And if you read the animal behavior journals, you'll see that this requirement sets the bar pretty high, so that many assertions about evolutionary psychology sink without a trace.

Jerry Coyne
Why Evolution Is TrueI once made the remark that two things disappeared in 1990: one was communism, the other was biochemistry and that only one of them should be allowed to come back.

Sydney Brenner
TIBS Dec. 2000
It is naïve to think that if a species' environment changes the species must adapt or else become extinct.... Just as a changed environment need not set in motion selection for new adaptations, new adaptations may evolve in an unchanging environment if new mutations arise that are superior to any pre-existing variations

Douglas Futuyma
One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.

Francis Crick
There will be no difficulty in computers being adapted to biology. There will be luddites. But they will be buried.

Sydney Brenner
An atheist before Darwin could have said, following Hume: 'I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one.' I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist

Richard Dawkins
Another curious aspect of the theory of evolution is that everybody thinks he understand it. I mean philosophers, social scientists, and so on. While in fact very few people understand it, actually as it stands, even as it stood when Darwin expressed it, and even less as we now may be able to understand it in biology.

Jacques Monod
The false view of evolution as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing programs that model evolution by natural selection.